1. Field of the Invention
The present invention is related to the field of rotary cutting tools, and more particularly to a cutting insert holder which facilitates easy removal and replacement of the cutting elements or cutting inserts used with rotary cutting tools.
2. Brief Description of the Prior Art
Rotary cutting tools are well known in the art. Such cutting tools have long been utilized in many fields of endeavor, such as the material shaping field, stone and concrete grinding, road surfacing, mining, tunnel construction, etc. In addition to the large sized road construction, mining, and tunnel construction machines, such cutting tools are commonly used in relatively small sized tools such as milling machines, lathes, boring tools, planing tools, etc. Cutting tools for these uses generally have one or more cutting inserts mounted thereon such that the cutting insert is fixed relative to its mounting or rotational with respect to such mounting. The cutting tool causes the cutting insert to engage the workpiece to cut a predetermined amount of material therefrom. In such cutting tools, many are provided with means for adjusting the position of the cutting insert with respect to a nominal or "zero" plane. Where more than one cutting insert is utilized on the tool, it is desirable to have all of the cutting inserts precisely adjusted to the same position with respect to the zero plane. Such adjustment, of course, is also desired in cutting tools in which only a single cutting insert is provided.
In some prior art rotary cutting tools, the cutting inserts are mounted on the cutting surface of the tool by use of a bolt or the like extending through the center of the insert and into a protruding base portion of the rotary cutting tool.
It is often desired to change the physical size of the cutting insert depending upon the machine operation being performed. Cutting tools heretofore available have, in general, not been able to accept cutting inserts of more than one size.
In many of the heretofore available cutting tools, it has been a comparatively time-consuming task to make the necessary adjustment of the cutting insert or inserts toward and away from the zero plane, and/or comparatively complex cartridge arrangements for holding the cutting inserts have been utilized with the consequent increase in cost and decrease in reliability associated with larger numbers of components.
Also, in the past, replacement of damaged or dulled cutting inserts involved a major disassembly of a rotary cutting tool. Such disassembly procedure is time-consuming, inconvenient, generally costly, and can involve a substantial waste of machining operating time.
There are some notable exceptions to the aforementioned lack in the prior art of addressing the several problems in the field of rotary cutting tools. Specifically, U.S. Pat. No. 4,477,211 provides cutting insert cartridges that permit new cutting inserts for rotary cutting tools to be easily, quickly, and cheaply replaced or installed. In U.S. Pat. No. 4,828,436, a cartridge assembly for a cutting insert in a rotary cutting tool is provided offering a high degree of precision adjustment of the cutting insert. Both rotating and fixed cutting inserts are shown in the '436 patent to be utilized interchangeably, and the removal and replacement of a cutting element is shown to be easily and quickly accomplished. The present invention offers an even further improvement over the inventions according to these prior U.S. patents by providing an extremely easily operated cutting insert removal and replacement function, as well as providing the ability to remove and replace the cutting insert holding cartridge for exchange with another cutting insert holding cartridge which will accept a different size cutting insert, all while maintaining a very precise zero plane position for the cutting edge of each cutting insert.